I have a 2003 2210. When I first start the tractor the lift arms go up fine, but they go down very slowly. After about 5 minutes they will go down if I stand on them, and shortly after that they won't go down at all. I don't have anything mounted on the back, but the lift arms control the mower deck height. This started slowly over a couple of weeks where it would go down slowly at first, then slower as time went on, but it was this week that it stopped going down at all. There is no problem with raising the lift arms, just lowing them. It doesn't matter if the cutting deck is on or off the tractor, the problem is the same.
After I turn the tractor off the arms are still stuck up, but if I leave the rockshaft control lever in the down position the arms are down by the next day. I have checked the rockshaft control knob and turned it from open to closed and back again with no change. The loader works fine and there is no problem with the hydrostatic drive. Today I changed the transmission fluid and filter and cleaned the suction screen. The screen had two long, thin magnets in it and they were covered with fine metal shavings. I bought this tractor used in 2009 and I don't know if the magnets are a first owner feature or factory. They don't quite fit right so I assume they are from the first owner, plus there is no mention of them in the manual. Either way I thought is was a good idea and put them back in when I reassembled everything. I bought the filter and fluid from the local JD dealer and made sure the fluid was at the correct level as indicated in the sight glass. I really thought this was going to fix it, but there is no change. Any help would be greatly appreciated.